US 4,299,070 · Granted 1981-11-10
The Interlocking Plastic Panel That Seals Itself as You Build
Imagine building blocks that snap together AND seal themselves against drafts at the same time. This patent describes plastic wall panels with a wedge-shaped groove system that lets you connect one panel to the next while creating an airtight barrier, keeping heat from escaping through the joints.
The plain-English version
What it protects
The claim covers a box-formed building panel made from extruded plastic with end walls that contain a specialized joining mechanism. What's protected here is the specific design where one panel has a wedge-shaped projection that inserts into a groove on an adjacent panel, with that groove containing a sealant material. The protection extends to variations where joinery and sealing are combined in a single construction, or kept separate as distinct projection-and-groove pairs. Internal stiffeners, auxiliary panels, and foam filling within the panel structure are also part of the claimed invention.
Why it matters
This patent represents an early approach to solving a major building problem: heat loss through seams. By combining the mechanical connection and thermal seal into one integrated system, manufacturers could reduce labor costs and improve energy efficiency without requiring separate gaskets or caulking steps. Extruded plastic panels became attractive alternatives to traditional construction materials because they're lightweight, moldable into complex shapes, and can be mass-produced consistently. This design potentially made prefabricated panel construction faster and more reliable for residential and commercial buildings.
Real-world use
When contractors assemble modular wall systems or prefabricated panel homes, they're often using interlocking panels where the joint itself becomes the thermal barrier, eliminating gaps that would let cold air leak through.
Original USPTO abstract
A box formed building panel has a section in the end walls that joins the panel to an adjacent panel and seals the joint against heat loss. The joining and sealing functions may be combined in a single construction, such as a wedge-shaped projection on one panel insertable into a sealant containing groove in the other panel, or, separate projection and groove combinations may be used for joinder and for sealing. Internal walls and stiffeners may be mounted in the building panel. The building panel may be filled with foam and auxiliary panels mounted on the building panel.
Patent details
- Publication number
- US 4,299,070
- Filing date
- 1979-06-21
- Grant date
- 1981-11-10
- Assignee
- Heinrich Oltmanns
- Inventor(s)
- OLTMANNS; HEINRICH, GRANZ; AXEL
- CPC class
- E04C2/543
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